Drafting and development is the lifeblood of any NHL organization, especially in this salary cap era.

Starting today in Buffalo, there will be a better idea on just how well the Bruins have done in those vital components. They kick off the preseason with a three-game rookie/prospects tournament against teams from the Sabres, Devils and Penguins organizations starting with a game against the Pens tonight.

When Don Sweeney took over the general manager’s job in the summer of 2015, he made a radical change to the organization by trading Milan Lucic and Dougie Hamilton for a bevy of first- and second-round picks. They’ve already hit on one of those players with defenseman Brandon Carlo and now, with many of the veteran core players nearing the backside of their prime, the B’s desperately need other prospects to become NHL players.

“It’s an important time for the organization and I think the players are excited about the opportunity as are we to start the evaluation process,” said Sweeney.

The B’s have a handful of roster spots open in their forward lines, and not just in the bottom six. The Patrice Bergeron line could be looking for a right winger, while the David Krejci unit needs a left winger. The list of candidates is long — Jake DeBrusk, Danton Heinen, Anders Bjork, Zach Senyshyn and Frank Vatrano, who is not eligible to play in the tourney.

Sweeney is hoping the youngsters give him some tough decisions to make.

“We’ve always stated that we want to be a deeper team, a deeper organization from top to bottom,” said Sweeney. “You have to have players that can push through and push other players out. We have potential spots, but we also have incumbents that don’t want to be giving spots up. We have players that broke through last year that will want to continue their own progressions. We have younger players that are coming on line that we’ve laid out that the opportunity is there but you’re the ones that have to take advantage of that. And we’ve seen players come out the gate strong and then, when the rest of the league gets better, they’ve stayed at the same level and they realize they have more work to do. That could happen, but we’re excited about the competition part.”

If enough players have the kind of camps that are hoped for, it could force Sweeney to make some moves with his roster.

But pushing veterans out is not easy.

“They have to definitively be better in order to make our hockey club better, so it could create some activity around the league,” said Sweeney. “I’m sure everybody is doing the same thing, thinking where’s their depth. We analyze all the other clubs throughout the year looking at other club’s depth and I’m sure they’re doing the same thing with us.”

Blue line jobs

There does not seem to be as much opportunity on the blue line as there is up front, but there is a pretty good group of aspiring defensemen in Buffalo, including Robbie O’Gara, Jakub Zboril, Jeremy Lauzon and Matt Grzelcyk.

Thanks to injuries last year, O’Gara played the first three games with the Bruins before being sent down to Providence. He didn’t look out of place with the big club, but didn’t get another call-up.

“I wouldn’t say I was surprised,” said O’Gara. “Really, what got me through training camp and throughout the year was just focusing on me and what I could do and not worry about who’s getting that call-up, doing what I can do to put myself in the best position to be that guy. As the year went on, I was getting better and feeling more comfortable. That’s all I can do and all I plan on doing moving forward.”

Pastrnak update

Sweeney had no progress to report to find a new deal for David Pastrnak, but it sounds as if the two sides have begun hashing it out in earnest.

“Status quo. (Pastrnak’s agent J.P. Barry) and I continue to talk and will continue to talk to find a way to get a deal at some point in time,” said Sweeney. “There’s no real timetable on it and nothing to really expand on other than to say the nature of the talks have been ongoing.”

The B’s offered a six- or seven-year deal worth $6 million per season while it is believed Pastrnak is looking for something in line with Edmonton’s Leon Draisaitl’s contract signed earlier in the summer, an eight-year pact worth $8.5 million a season.

The sides have until Dec. 1 to reach a deal or Pastrnak would be ineligible to play this season.

Sweeney would ideally like the winger here when training camp begins next Thursday.

“I was on record awhile ago and I heard one of the general managers (Wednesday) talking about how nobody really hides from the fact that I don’t think (missing camp is) productive for either side,” said Sweeney, who added that both sides remain committed to making Pastrnak a Bruin for many years to come.

“There’s never really been any deviance from that standpoint, from the organization or the player.”